Increased urinary creatinine during hibernation and day roosting in the Eastern bent-winged bat (Miniopterus fuliginosus) in Korea

• Published in: Communications biology Vol. 7; no. 1; p. 42
• Main Authors: Ryu, Heungjin, Kinoshita, Kodzue, Joo, Sungbae, Choi, Yu-Seong, Kim, Sun-Sook
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.01.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/158/2455; 631/158/856; Arousal; Biomedical and Life Sciences; Creatinine; Hibernation; Ketonuria; Life Sciences; Metabolism; Miniopterus fuliginosus; Reabsorption; Torpor; Urine; Water balance; Water management; Water stress
• ISSN: 2399-3642; 2399-3642
• DOI: 10.1038/s42003-023-05713-1

Torpor and arousal cycles, both daily and seasonal (e.g. hibernation), are crucial for small mammals, including bats, to maintain the energy and water balance. The alternation between torpor and arousal leads to metabolic changes, leaving traceable evidence of metabolic wastes in urine. In this study we investigated urinary creatinine and acetoacetate (a ketone body) in the Eastern bent-wing bat ( Miniopterus fuliginosus ) in Mungyeong, South Korea. We found an increase in urinary creatinine during torpor in summer, indicating changes in renal water reabsorption rates during the active season. Although we could not confirm ketonuria in hibernating bats due to a methodological limitation caused by the small amount of urine, we verified an increase in urinary creatinine concentration during hibernation. This finding suggests that managing water stress resulting from evaporative water loss is one of key reasons for arousal during hibernation in Eastern bent-wing bats. A study on metabolic markers in urine from Eastern bent-winged bats demonstrates seasonal and individual variations in water-stress that suggest an association between water-stress and winter arousal.